Characteristics of inorganic phosphorus fractions and their correlations with soil properties in three non-acidic soils

Understanding the characteristics and influences of various factors on phosphorus(P)fractions is of significance for promoting the efficiency of soil P.Based on long-term experiments on black soil,fluvo-aquic soil,and loess soil,which belong to Phaeozems,Cambisols,and Anthrosols in the World Reference Base for Soil Resources(WRB),respectively,five fertilization practices were selected and divided into three groups:no P fertilizer(CK/NK),balanced fertilizer(NPK/NPKS),and manure plus mineral fertilizer(NPKM).Soil inorganic P(Pi)fractions and soil properties were analyzed to investigate the characteristics of the Pi fractions and the relationships between Pi fractions and various soil properties.The results showed that the proportion of Ca_(10)-P in the sum of total Pi fractions was the highest in the three soils,accounting for 33.5%in black soil,48.8%in fluvo-aquic soil,and 44.8%in loess soil.Long-term fertilization practices resulted in periodic changes in soil Pi accumulation or depletion.For black soil and fluvo-aquic soil,the Pi accumulation was higher in the late period(10–20 years)of fertilization than in the early period(0–10 years)under NPK/NPKS and NPKM,whereas the opposite result was found in loess soil.The Pi accumulation occurred in all Pi fractions in black soil;mainly in Ca_(8)-P,Fe-P,and Ca_(10)-P in fluvo-aquic soil;and in Ca_(2)-P,Ca_(8)-P,and O-P in loess soil.Under CK/NK,the soil Pi was depleted mainly in the early period in each of the three soils.In addition to the labile Pi(Ca_(2)-P)and moderately labile Pi(Ca_(8)-P,Fe-P,Al-P),the Ca_(10)-P in black soil and fluvo-aquic soil and O-P in loess soil could also be used by crops.Redundancy analysis showed that soil properties explained more than 90%of the variation in the Pi fractions in each soil,and the explanatory percentages of soil organic matter(SOM)were 43.6%in black soil,74.6%in fluvo-aquic,and 38.2%in loess soil.Consequently,decisions regarding the application of P fertilizer should consider the accumulation rate and the variations in Pi fractions driven by soil properties in non-acidic soils.

Extending MoS_(2)-based materials into the catalysis of non-acidic hydrogen evolution:challenges,progress,and perspectives

Water splitting is regarded as among the most prospective methods of generating green hydrogen.Switching electrolytes of water electrolysis from acidic to non-acidic ones will enable the use of noble-metal-free electrocatalysts and mitigate material corrosion,thus lowering the capital cost of water electrolyzers and improving their operational stability.However,increasing electrolyte pH will degrade the hydrogen evolution reaction(HER)activity because of the reduced concentration of H_(3)O^(+)as reactants,making non-acidic HER sluggish.To accelerate HER,MoS_(2)-based materials with the advantages of unique atomistic structure,low cost,and high abundance have been considered prospective electrocatalysts to substitute for Pt in acid.Great efforts are being spent on extending MoS_(2)-based materials into the catalysis of non-acidic HER,and their further development requires clarification of the existing challenges and current progress.However,it has not yet been discussed for non-acidic HER on MoS_(2)-based electrocatalysts.To mitigate the disparity,we systematically overview MoS_(2)-based electrocatalysts for non-acidic HER,covering catalytic mechanisms,modulation strategies,materials development,current challenges,research progress,and perspectives.This review will contribute to the rational design of MoS_(2)-based materials for high-performance HER in non-acidic conditions.

Acid and non-acid reflux in patients refractory to proton pump inhibitor therapy:Is gastroparesis a factor?

AIM:To determine whether an increased number and duration of non-acid reflux events as measured using the multichannel intraluminal impedance pH(MII-pH)is linked to gastroparesis(GP).METHODS:A case control study was conducted in which 42 patients undergoing clinical evaluation for continued symptoms of gastroesophageal reflux disease(both typical and atypical symptoms)despite acid suppression therapy.MII-pH technology was used over 24 h to detect reflux episodes and record patients’symptoms.Parameters evaluated in patients with documented GP and controls without GP by scintigraphy included total,upright,and supine number of acid and non-acid reflux episodes(pH<4 and pH>4,respectively),the duration of acid and non-acid reflux in a 24-h period,and the number of reflux episodes lasting longer than 5 min.RESULTS:No statistical difference was seen between the patients with GP and controls with respect to the total number or duration of acid reflux events,total number and duration of non-acid reflux events or the duration of longest reflux episodes.The number of nonacid reflux episodes with a pH>7 was higher in subjects with GP than in controls.In addition,acid reflux episodes were more prolonged(lasting longer than 5min)in the GP patients than in controls;however,these values did not reach statistical significance.Thirty-five patients had recorded symptoms during the 24 h study and of the 35 subjects,only 9%(n=3)had a positive symptom association probability(SAP)for acid/non-acid reflux and 91%had a negative SAP.CONCLUSION:The evaluation of patients with a documented history of GP did not show an association between GP and more frequent episodes of non-acid reflux based on MII-pH testing.

Gastroesophageal reflux disease:From pathophysiology to treatment

This review focuses on the pathophysiology of gastroesophageal reflux disease (GERD) and its implications for treatment. The role of the natural anti-reflux mechanism (lower esophageal sphincter, esophageal peristalsis, diaphragm, and trans-diaphragmatic pressure gradient), mucosal damage, type of refluxate, presence and size of hiatal hernia, Helicobacter pylori infection, and Barrett’s esophagus are reviewed. The conclusions drawn from this review are: (1) the pathophysiology of GERD is multifactorial; (2) because of the pathophysiology of the disease, surgical therapy for GERD is the most appropriate treatment; and (3) the genesis of esophageal adenocarcinoma is associated with GERD.

Analysis of Waste-Rock Transportation Process Performance in an Open-Pit Mine Based on Statistical Analysis of Cycle Times Data

In this paper, the performance of a waste rock transportation process in an open pit mine was assessed by using cycle time data. A computerized truck-excavator dispatch system was used to record the cycle times. The process was broken into seven steps (or components of the total cycle), durations of which were recorded for a period of 1 month, leading to N = 60,690 data points or dispatches. The open pit mine studied consisted of 12 waste types loaded by 14 excavators and hauled by 49 trucks (at a trucks-to-excavator ratio of 3.5:1) in 75 changing locations. The string-type data was coded using integers to allow a FORTRAN code to extract process performance parameters using statistical analysis. The study established a wide range of parameters including: the waste material generation rate (about 1.73 million t/month, 81% comprising waste rock), truck fill factor, f, total cycle time (Tct), production capacity, theoretical cycle time, non-productive cycle time Tnp, and cycle time performance ratio (CTPR), denoted as Tpr. The factors affecting the process performance include: truck model, excavator model, location (haul distance and road conditions) and material type. For a fixed material type and tonnage, the PDFs of the cycle time components were logarithmic in nature, capable of differentiating performance variations under different factors. It was concluded that the performance of the waste material transportation system in this mine was determined to be acceptable due to mean value of Tpr = 2.432 being closer to unity. Reduction measures were suggested to minimize the cycle time for the process bottlenecks determined from Pareto analysis (that is, full haul, empty haul and loading processes).

Investigation of Excavator Performance Factors in an Open-Pit Mine Using Loading Cycle Time

This study presents the effect of excavator model, loading operation location, shift availability and truck-shovel combination on loading cycle time and productivity of an open-pit mine. The loading cycle time was used to assess the material loading system performance which is one of the key components of the total cycle time for material transportation in an open-pit mine. Loading is among the components of cycle time during which material is being handled. The data analyzed?was?collected from a computerized dispatch system at GGM from which 62,000 loading dispatches per month involving several shifts, 14 excavators and 49 trucks were loaded. About 4465 dispatches per excavator and 1276 dispatches per truck were assessed using loading cycle time data for each dispatch for a period of four months (between August and December). Under fixed tonnage loaded and waste type (33 t of non-acid forming waste rock),?it was observed that loading cycle time depends on excavator model, location and truck being loaded. Average cycle times, PDFS?and CDFS of loading cycle time series were used to identify differences in performance under different situations. It was concluded that shift availability for excavators, loading location, excavator model and truck-shovel combinations strongly affect the productivity during loading process in an open-pit mine.

Tropifexor,a selective non-acid farnesoid X receptor agonist,improved nonalcoholic steatohepatitis in a phase 2 trial,but several issues remain to be resolved

As obesity continues to escalate worldwide,nonalcoholic fatty liver disease(NAFLD)has emerged as the most prevalent form of liver disease,with a reported global prevalence of 30.1%(1).The prevalence of NAFLD,which was around 25%in the 1990s,has been increasing year by year in recent years and has exceeded 35%in the past few years(1).The spectrum of disease includes nonalcoholic fatty liver(NAFL),characterized by macrovesicular hepatic steatosis that may be accompanied by mild inflammation,and nonalcoholic steatohepatitis(NASH),which is additionally characterized by the presence of inflammation and cellular injury(2).